Kinetic studies on using photocatalytic coatings for removal of indoor volatile organic compounds

Abstract

Titanium dioxide (TiO2) is a known photocatalyst with a capability of decomposing organic substance. However, the photocatalysis of the pure TiO2 is not effective for the indoor environment due to a lack of the ultraviolet irradiation inside the building. Doping TiO2 with substance such as C, N or metal can extend the threshold of the absorption spectrum to the visible spectrum region.Thus, doped-TiO2 is able to decompose volatile organic compounds (VOCs) under an indoor environment. To date, most experimental work reported on photocatalytic kinetics were conducted inside small-scale devices. The performance of air purification function under the actual indoor application scenery need to be further clarified. For this purpose, it is crucial to predict the performance of autogenous air quality improvements by visible light driven photocatalyst for the actual applications. This work has developed a model to evaluate the performance of functional coating with photocatalyst in removing VOCs. Factors such as the effects of coating designs and indoor ambient conditions on the air purification efficiency were studied. This work demonstrates that doped-TiO2 photocatalytic coating is effective to improve the indoor air quality. Summary of the practical implicationsThe kinetics of doped-TiO2 on removal of VOCs are simulated in the actual size room, rather than that in the small-size devices. This work demonstrates that doped-TiO2 photocatalytic coating is effective to remove the volatile organic compounds with a reasonable dosage of photocatalyst at a comparable rate to ventilation. We believe this work fills a knowledge gap for removing the indoor air contaminants from the large-scale dimensional aspect. It should be feasible to fabricate commercial membranes coated with doped-TiO2 for indoor air purification.

Performance and Mechanism of Chlorine Dioxide on BTEX Removal in Liquid and Indoor Air

“…The photocatalytic method utilizes light-induced semiconductor production of •OH to oxidize BTEX. Photocatalysis has high photoactivity and a rapid reaction speed [28][29][30]. Chen et al, synthesized a non-noble amorphous SnO 2 -modified ZnSn(OH) 6 (ZSH) photocatalyst by the in situ method.…”

Effect of environmental factors on the concentration distribution of bioaerosols with different particle sizes in an enclosed space

“…Human beings spend most of their lives indoors, thus the quality of the indoor environment is closely related to human health. 1 As one of the important indexes of indoor air quality, indoor bioaerosols have been receiving important considerations. [2][3][4] Bioaerosols are particulate matter (including solid or liquid) combined with biological sources, typically such as fungi, bacteria, viruses, pollen, etc.…”

Numerical evaluation of contaminants mixing uniformity in a full-scale test chamber with mixing fan

“…In these research methods and standards, a VOC/ SVOC source material or an air cleaner is placed in the test device, and air contaminant in the device is detected to determine VOC/SVOC mass transport parameter or to evaluate the air cleaner performance. Among the existing test devices, the field and laboratory emission cell (FLEC), 6 chamber for laboratory investigations of materials, pollution and air quality (CLIMPAQ) 7 and small-scale environmental chamber 8,9 are widely adopted. 10 For example, Yang 8 measured the VOC emission from two particleboard specimens and styrene-butadiene rubber carpet in a small-scale environmental chamber.…”